解决 Spring Cloud 的服务应用配置 context-path 后 Spring Cloud Hystrix Turbine 监控不到信息的问题
在 Spring Cloud 应用篇 之 Hystrix Turbine（断路器聚合监控）的基本搭建 这篇文章中，讲解了 Spring Cloud Hystrix Turbine 集群监控服务，但是，如果被监控的服务配置了 context-path 这个属性，那么，你的监控就会出现问题，就如同 Spring Boot Admin 监控出现的问题一样，关于 Spring Boot Admin 的这个问题，可以看一下这篇文章：解决 Spring Cloud 的服务应用配置 context-path 后 Spring Boot Admin 监控不到信息的问题。言归正传，下面我们接着分析服务配置了 context-path 后 Hystrix Turbine 聚合监控不到的问题。
（一）被监控的服务都配置了 context-path 属性
拿之前文章里写的服务 spring-demo-service-feign 做例子
spring-demo-service-feign 的配置文件，添加 context-path 的配置如下：
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
# 如果项目配置有 server.servlet.context-path 属性，想要被 spring boot admin 监控，就要配置以下属性
instance:
metadata-map:
management:
context-path: /gateway/actuator
# 解决配置了 context-path 后 spring boot admin 监控第一种方案
# health-check-url: http://localhost:${server.port}/gateway/actuator/health
# status-page-url: http://localhost:${server.port}/gateway/actuator/info
# home-page-url: http://localhost:${server.port}/
# 解决配置了 context-path 后 spring boot admin 监控的第二种方案（优化）
health-check-url-path: /gateway/actuator/health
server:
port: 8382
servlet:
context-path: /gateway
spring:
application:
name: spring-demo-service-feign
feign:
hystrix:
enabled: true
# Ribbon 的负载均衡策略
spring-demo-service:
ribbon:
NFLoadBalancerRuleClassName: com.netflix.loadbalancer.BestAvailableRule
management:
endpoints:
web:
exposure:
include: '*'
endpoint:
health:
show-details: ALWAYS
info:
version: 1.0.0启动 eureka server、spring-demo-service、spring-demo-service-feign、spring-cloud-hystrix-dashboard-turbine 服务
访问 http://localhost:8581/hystrix，输入 http://localhost:8581/turbine.stream，点击 Monitor Stream，发现界面一直是 Loading...状态，之前说过这个可能是因为没有请求数据，那么我们就访问一下接口
访问 http://localhost:8382/gateway/hello
接口已访问，为了证明此时已经有 hystrix 的数据，我们访问一下 http://localhost:8382/gateway/actuator/hystrix.stream
可见，已经产生数据了，此时刷新 hystrix turbine 的界面，你会发现仍然是 Loading 界面，这就是因为我们服务配置了 context-path 的原因，解决这个问题也很简单，只需要做一些配置即可，具体原理我们等下再说，先给出解决方案
修改 spring-cloud-hystrix-dashboard-turbine 服务的配置如下，重启 spring-cloud-hystrix-dashboard-turbine
server:
port: 8581
spring:
application:
name: spring-cloud-hystrix-dashboard-turbine
turbine:
# 1.被监控的服务应用没有配置 context-path 的情况下
# 配置 Eureka 中的 serviceId 列表，指定要监控的服务
# app-config: SPRING-DEMO-SERVICE-FEIGN,SPRING-DEMO-SERVICE-RIBBON
# aggregator:
# cluster-config: default
# # 指定集群名称
# cluster-name-expression: "'default'"
# 2.被监控的服务应用配置了 context-path 的情况下，此时默认是集群里的应用都配置了 context-path
# 配置 Eureka 中的 serviceId 列表，指定要监控的服务
app-config: SPRING-DEMO-SERVICE-FEIGN
aggregator:
cluster-config: default
# 指定集群名称
cluster-name-expression: "'default'"
instanceUrlSuffix: gateway/actuator/hystrix.stream
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka/
management:
endpoints:
web:
exposure:
include: '*'
endpoint:
health:
show-details: ALWAYS重新执行访问 http://localhost:8581/hystrix，输入 http://localhost:8581/turbine.stream 的步骤，界面如下，可以看到，已经监控到了 spring-demo-service-feign
这种情况是被监控的服务都配置了 context-path 属性，如果被监控的服务一部分配置了 context-path，另外一些没有配置呢，也很好办，把配置了 context-path 属性的服务聚合为一个集群，没有配置的服务作为另一个集群，具体如下
（二）被监控的服务部分配置了 context-path
仍然是拿之前的服务作为例子，spring-demo-service-ribbon（没有配置 context-path）、spring-demo-service-feign（配置了 context-path）
修改 spring-cloud-hystrix-dashboard-turbine 的配置文件：
server:
port: 8581
spring:
application:
name: spring-cloud-hystrix-dashboard-turbine
turbine:
# 1.被监控的服务应用没有配置 context-path 的情况下
# 配置 Eureka 中的 serviceId 列表，指定要监控的服务
# app-config: SPRING-DEMO-SERVICE-FEIGN,SPRING-DEMO-SERVICE-RIBBON
# aggregator:
# cluster-config: default
# # 指定集群名称
# cluster-name-expression: "'default'"
# 2.被监控的服务应用配置了 context-path 的情况下，此时默认是集群里的应用都配置了 context-path
# 配置 Eureka 中的 serviceId 列表，指定要监控的服务
# app-config: SPRING-DEMO-SERVICE-FEIGN
# aggregator:
# cluster-config: default
# # 指定集群名称
# cluster-name-expression: "'default'"
# instanceUrlSuffix: gateway/actuator/hystrix.stream
# 3.被监控的服务应用一部分配置了 context-path，一部分没有配置 context-path
# 配置 Eureka 中的 serviceId 列表，指定要监控的服务
app-config: SPRING-DEMO-SERVICE-FEIGN,SPRING-DEMO-SERVICE-RIBBON
aggregator:
cluster-config: SPRING-DEMO-SERVICE-FEIGN,SPRING-DEMO-SERVICE-RIBBON
# 指定集群名称
cluster-name-expression: metadata['cluster']
instanceUrlSuffix:
SPRING-DEMO-SERVICE-FEIGN: gateway/actuator/hystrix.stream
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka/
management:
endpoints:
web:
exposure:
include: '*'
endpoint:
health:
show-details: ALWAYS
spring-demo-service-ribbon 作为一个集群，spring-demo-service-feign 作为一个集群，然后对 spring-demo-service-feign 集群做特俗配置，只做这些配置还不够，还需要对 spring-demo-service-ribbon 和 spring-demo-service-feign 的配置进行修改，具体修改如下：
spring-demo-service-ribbon 的配置文件：
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
instance:
metadata-map:
cluster: SPRING-DEMO-SERVICE-RIBBON
server:
port: 8381
spring:
application:
name: spring-demo-service-ribbon
spring-demo-service:
ribbon:
NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule
management:
endpoints:
web:
exposure:
include: '*'
endpoint:
health:
show-details: ALWAYSspring-demo-service-feign 的配置文件：
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
# 如果项目配置有 server.servlet.context-path 属性，想要被 spring boot admin 监控，就要配置以下属性
instance:
metadata-map:
cluster: SPRING-DEMO-SERVICE-FEIGN
management:
context-path: /gateway/actuator
# 解决配置了 context-path 后 spring boot admin 监控第一种方案
# health-check-url: http://localhost:${server.port}/gateway/actuator/health
# status-page-url: http://localhost:${server.port}/gateway/actuator/info
# home-page-url: http://localhost:${server.port}/
# 解决配置了 context-path 后 spring boot admin 监控第二种方案（优化）
health-check-url-path: /gateway/actuator/health
server:
port: 8382
servlet:
context-path: /gateway
spring:
application:
name: spring-demo-service-feign
feign:
hystrix:
enabled: true
# Ribbon 的负载均衡策略
spring-demo-service:
ribbon:
NFLoadBalancerRuleClassName: com.netflix.loadbalancer.BestAvailableRule
management:
endpoints:
web:
exposure:
include: '*'
endpoint:
health:
show-details: ALWAYS
info:
version: 1.0.0可以看到，都是添加了 eureka.instance.metadata-map.cluster 这个属性，这个属性就是设置服务的集群。
至此，配置已全部完成，依次启动服务，访问 http://localhost:8581/hystrix，此时就不是填写 http://localhost:8581/turbine.stream 了，而是要加上集群名，如：http://localhost:8581/turbine.stream?cluster=SPRING-DEMO-SERVICE-RIBBON，可以看到，已经成功监控
再来看看对 spring-demo-service-feign 的监控，输入：http://localhost:8581/turbine.stream?cluster=SPRING-DEMO-SERVICE-FEIGN，可以看到也成功监控了
（三）简单的源码分析
源码在 spring-cloud-netflix-turbine 的 jar 包下，具体在 org.springframework.cloud.netflix.turbine.SpringClusterMonitor 这个类，源码如下：
public class SpringClusterMonitor extends AggregateClusterMonitor {
// TODO: convert to ConfigurationProperties (how to do per-cluster configuration?
public SpringClusterMonitor(String name, String clusterName) {
super(name, new ObservationCriteria.ClusterBasedObservationCriteria(clusterName),
new PerformanceCriteria.AggClusterPerformanceCriteria(clusterName),
new MonitorConsole(), InstanceMonitorDispatcher,
SpringClusterMonitor.ClusterConfigBasedUrlClosure);
}
/**
* TODO: make this a template of some kind (secure, management port, etc...) Helper
* class that decides how to connect to a server based on injected config. Note that
* the cluster name must be provided here since one can have different configs for
* different clusters
*/
public static InstanceUrlClosure ClusterConfigBasedUrlClosure = new InstanceUrlClosure() {
private final DynamicStringProperty defaultUrlClosureConfig = DynamicPropertyFactory
.getInstance().getStringProperty("turbine.instanceUrlSuffix",
"actuator/hystrix.stream");
private final DynamicBooleanProperty instanceInsertPort = DynamicPropertyFactory
.getInstance().getBooleanProperty("turbine.instanceInsertPort", true);
@Override
public String getUrlPath(Instance host) {
if (host.getCluster() == null) {
throw new RuntimeException(
"Host must have cluster name in order to use ClusterConfigBasedUrlClosure");
}
// find url
String key = "turbine.instanceUrlSuffix." + host.getCluster();
DynamicStringProperty urlClosureConfig = DynamicPropertyFactory.getInstance()
.getStringProperty(key, null);
String url = urlClosureConfig.get();
if (url == null) {
url = this.defaultUrlClosureConfig.get();
}
if (url == null) {
throw new RuntimeException("Config property: "
+ urlClosureConfig.getName() + " or "
+ this.defaultUrlClosureConfig.getName() + " must be set");
}
// find port and scheme
String port;
String scheme;
if (host.getAttributes().containsKey("securePort")) {
port = host.getAttributes().get("securePort");
scheme = "https";
} else {
port = host.getAttributes().get("port");
scheme = "http";
}
if (host.getAttributes().containsKey("fusedHostPort")) {
return String.format("%s://%s/%s", scheme, host.getAttributes().get("fusedHostPort"), url);
}
// determine if to insert port
String insertPortKey = "turbine.instanceInsertPort." + host.getCluster();
DynamicStringProperty insertPortProp = DynamicPropertyFactory.getInstance()
.getStringProperty(insertPortKey, null);
boolean insertPort;
if (insertPortProp.get() == null) {
insertPort = this.instanceInsertPort.get();
}
else {
insertPort = Boolean.parseBoolean(insertPortProp.get());
}
// format url with port
if (insertPort) {
if (url.startsWith("/")) {
url = url.substring(1);
}
if (port == null) {
throw new RuntimeException(
"Configured to use port, but port or securePort is not in host attributes");
}
return String.format("%s://%s:%s/%s", scheme, host.getHostname(), port, url);
}
//format url without port
return scheme + "://" + host.getHostname() + url;
}
};
} 可以看到源码里有这个操作：
private final DynamicStringProperty defaultUrlClosureConfig = DynamicPropertyFactory
.getInstance().getStringProperty("turbine.instanceUrlSuffix",
"actuator/hystrix.stream");就是获取 turbine.instanceUrlSuffix 这个配置，如果没有配置，默认值就是 actuator/hystrix.stream，而当我们给服务配置了 context-path 后，这个 url 肯定取不到信息，所以我们配置了 turbine.instanceUrlSuffix = gateway/actuator/hystrix.stream，这个配置即可解决默认集群中全部配置了 context-path 属性的问题
接着我们看到还有这一步操作：
String key = "turbine.instanceUrlSuffix." + host.getCluster();
DynamicStringProperty urlClosureConfig = DynamicPropertyFactory.getInstance()
.getStringProperty(key, null);这就可以和我们配置的 turbine.instanceUrlSuffix.SPRING-DEMO-SERVICE-FEIGN = gateway/actuator/hystrix.stream 对应上了，它会通过 turbine.instanceUrlSuffix. 加上集群名获取到我们在配置文件里配置的信息
至此，我们就解决了服务配置了 context-path 后，Turbine 监控不到的问题，如果想详细了解其原理，可以查阅相关源码和文档。
源码下载：https://github.com/shmilyah/spring-cloud-componets